Plexpress, creator of the innovative TRAC (Transcript Analysis with the aid of Affinity Capture) platform, has recently added to its growing library of pre-validated probes for multiplexed gene expression analysis. This includes many genes relevant for the investigation of in vitro drug interactions during pre-clinical studies, such as key members of the Cytochrome P450 family and many membranous transport channels.

Researchers can now select from hundreds of genes and carry out reliable, accurate and cost-effective ADME-Tox studies in a range of model systems, including human hepatocytes and rat liver tissue, with high sample throughput. While the pre-validated panels are perfect for ‘off-the-shelf’ use, the TRAC system can also be set-up and optimized for any gene where the sequence is known, providing researchers with the flexibility to investigate any gene combination using both novel and pre-validated probes.

Jari Rautio, Ph.D., CEO of Plexpress, commented: “TRAC is ideal for ADME-Tox studies as it allows the rapid analysis of an investigational drug in many thousands of samples, without sacrificing the number of genes being analyzed. New compounds likely to be toxic or ineffective can therefore be identified early in the process, before costly clinical trials have taken place.”

The use of gene expression to analyze ADME-Tox profiles is widespread in drug discovery, a trend that is likely to continue given a recent draft from report from the FDA suggesting that drug discovery researchers use CYP mRNA induction, rather than CYP activity, to assess drug metabolism and activity.

Dr Rautio continued: “The TRAC approach has already proved very popular with Biotech, Pharma and Contract Research Organizations, as it offers significant accuracy, speed and cost benefits over more traditional targeted approaches such as qPCR. To-date TRAC been used by over 100 studies to investigate gene expression in a range of experimental systems.”

TRAC uses 96-well plates and avoids the need for RNA extraction, cDNA conversion and amplification, reducing experimental bias. It can also multiplex up to 30 genes per sample, providing expression profiles for all key genes in a single, fast experiment, while minimizing technical variation. The Plexpress Human ADME-Tox panels can feature up to 6 reference genes and numerous targets including 14 CYP450 genes, glucuronosyl transferases, glutathione transferases and ABC transporters. The Plexpress rat ADME-Tox library has over 14 reference genes and more than 120 targets to choose from including hepatotoxicity, necrosis, cholestasis and steatosis markers as well as those associated with drug metabolism and transport pathways.

Depending on the needs of each project, Plexpress can process user’s samples via its ISO9001 certified FAST TRAC gene expression service or assist with setting up TRAC in a user’s own laboratory. TRAC is compatible with most third party magnetic bead processors and capillary electrophoresis devices. Plexpress also offers a ‘one-stop-shop’ for studies requiring fully integrated gene discovery, validation and in-depth analysis. The OneTRAC™ service, offered in collaboration with the Phalanx Biotech Group, combines the coverage breadth of Phalanx Biotech’s OneArray® microarrays with the high-throughput, multiplex capabilities of targeted TRAC analysis, allowing researchers to identify, select and validate a robust set of highly-relevant gene expression signatures. As well as its application in biomarker development, the OneTRAC™ service is fully capable of addressing the diverse needs of academic research projects and drug discovery programs alike.